Re: [PATCH] HID: Sony: Add support for Gasia controllers

[Roderick Colenbrander]

On Thu, Feb 6, 2020 at 12:10 AM Benjamin Tissoires
<benjamin.tissoires@xxxxxxxxxx> wrote:
>
> Hi,
>
> On Mon, Feb 3, 2020 at 12:23 PM Jiri Kosina <jikos@xxxxxxxxxx> wrote:
> >
> > On Mon, 3 Feb 2020, Benjamin Tissoires wrote:
> >
> > > I am definitely not in favour of that :(
> > >
> > > The basic problem we have here is that some vendors are overriding your
> > > VID/PIDs, and this is nasty. And I do not see any reasons why you can't
> > > say: "well, we broke it, sorry, but we only support *our* devices, not
> > > third party ones".
> >
> > Well, it's not about "we broke it" in the first place, as far as I
> > can tell.
> >
> > Roderick's concern is that 3rd party devices with overriden VID/PID
> > malfunction for completely unrelated reason to (correctly working) changes
> > done in favor of stock Sony devices, but it'll be Sony receiving all the
> > reports/blame.
>
> After re-reading the code, I am not sure we can easily detect the
> clones. So at some point, I think we will break them, but there is not
> much we can do. I don't really have a solution for that :(
>
> >
> > > One thing that comes to my mind (probably not the best solution), is to
> > > taint the kernel if you are facing a non genuine product. We do that for
> > > nvidia, and basically, we can say: "well, supporting the nvidia blob is
> > > done on a best effort case, and see with them directly if you have an
> > > issue". Tainting the kernel is a little bit rough, but maybe adding an
> > > info message in the dmesg if you detect one of those can lead to a
> > > situation were we can count on you for supporting the official products,
> > > and you can get community support for the clones.
> >
> > Yeah; which I wouldn't like to do for upstream kernel, but Sony could
> > definitely do this for the products they ship.
> >
> > The same way distros are tainting their kernels when unsupported modules
> > (but otherwise perfectly fine wrt. GPL and everything else) are loaded
> > into distro-supported kernels.
> >
> > > One last thing. Roderick, I am not sure if I mentioned that or not, but
> > > I am heavily adding regression tests for HID in
> > > https://gitlab.freedesktop.org/libevdev/hid-tools/
> >
> > ... and words can't express how thankful I am for that :)
> >
>
> OK, I played with that idea earlier this week:
> https://gitlab.freedesktop.org/libevdev/hid-tools/merge_requests/74
> I only have a Sixaxis controller, and I only implemented the USB part
> of it (AFAICT).
> Currently this ensures the button mapping is correct, and that the
> LEDs are working properly.
> We are still missing a few bits and pieces, but the initialization
> (requests made by the kernel to start the device and press on the PS
> button) is handled properly.
>
> If this is something Roderick would be interested in, we can then try
> to extend this initial work on Bluetooth controllers and the DualShock
> ones.

We can probably help out there (need to ask official permission). We
have similar tests in Android (still adding more). Just in case you
are not familiar this is their framework:
https://android.googlesource.com/platform/cts/+/master/tests/tests/hardware/src/android/hardware/input/cts/tests/

It is a small Java class and then there is a json blob with the actual
test (forgot where the json is). It defines the report descriptors
etcetera.

Thanks,
Roderick

> Adding the clones ones based on the current kernel code is something
> doable, but I do not expect Sony to be involved in that process.
>
> That being said, before we merge this particular patch about Gasia
> controllers, now we need to implement a regression test first :)
>
> Cheers,
> Benjamin
>